Interlocking relay



April 7..1931.

W. K. LOCKHART ET AL INT'ERLOCKING. RELAY .Fil-ed Dec. 23, 1929 2 Sheets-Sheet l ta r a NME. 9 1? 0O M M w ,v Gm.

Patented Apr. 7, 1931 1 UNITED STATES PATENT OFFICE WILLIAM K. LOCKHART, OF WILKINSBURG, AND THOMAS J. OMEARA, OF PITTSBURGH, PENNSYLVANIA, ASSIGNORS TO THE UNION SWITCH & SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA INTER-LOCKING RELAY Application filed December 23, 1929. Serial No. 416,016.

Our invention relates to interlocking relays, and particularly to interlocking relays in which two armatures controlled by separate electrcmagnets are interconnected by mechanical means .in such manner that when one armature moves away from its associated electromagnet, subsequent movement of the other armature away from its associated electromagnet is restricted.

We will describe one form of relay embodying our invention, and will then point out tl e novel features thereof in claims.

In the accompanying drawings, Fig. 1 is a view showing, in front elevation, one form of interlocking relay embodying our invention. Fig. 2 is a sectional view on the line IIII of Fig. 1. Fig. 3 is an isometric view of a portion of the relay shown in Figs. 1 and 2.

Similar reference characters refer to similar parts in all three views.

Referring first to Figs. 1 and 2, the relay, in the form here shown, comprises two similar electromagnets A and B mounted side by side on a top plate C of insulating material. The cores of the electromagnet Aare connected together at their upper ends in the usual manner by a back strap 1, and terminate at their lower ends in enlarged pole pieces 2 located beneath the top plate C, while the cores of the electromagnet B are similarly connected together at their upper ends by a back strap 1 and terminate at their lower ends in enlarged pole pieces 2 also located beneath the top plate G.

The electromagnet A controls an armature 5 pivotally supported on pivot pins 45 carried by the downwardly extending lugs of a bracket 3* fastened to the sides of the pole pieces 2. Attached to the underside of the armature 5 by means of insulating supports 7 (see Fig. 2) are contact fingers '8, here shown as two in number. When the electromagnet A is energized, the armatureb is drawn upwardly against non-magnetizable stops 6*, and the contact fingers 8 then each engage a front contact t) fastened by means of a holder 10 to a terminal. post 11 carried by the top plate C. WVhen electromagnet A is de-energized, however, the armature 5 drops downwardly under the influence of gravity, and except under conditions which will be explained hereinafter, the contact fingers 8 then each engage a back contact 12 attached to a terminal post 13 carried by the top plate C. In similar manner, the electromagnet B controls an armature 5' pivotally supported on pivot pins 4 carried by the downwardly extending lugs'of a bracket 3" fastened to the sides of the pole pieces 2. Contact fingers 8 are attached to the underside of the armature 5 'by supports which are not shown in the drawing but which are similar to the supports 7" shown in Fig. 2. The contact fingers 8 coact with front contacts 9 and back contacts 12 in the same manner as the contact fingers 8 coact with the front contacts 9 and the back contacts 12 as will be readily understood. from an inspection of the drawing.

Also attached to the armatures 5 and 5", respectively, are two interlocking arms 14 and 14 which cooperate with two lockingdogs 21 and 22 for at times restricting downward movement of the corresponding armatures. The locking dogs 21 and 22, are pivoted on a horizontal shaft 25 carried by a yoke 26 attached to the top plate(] by screws 29. The dogs are held in proper spaced relation on the shaft 25 by separators 28. The dog 21 is provided with a horizontal arm 21 and a vertical arm 21, and the dog 22 is similarly provided with a horizontal arm 22* and a vertical arm 22". The horizontal arm 21 is provided at one end with a counterweight 23 and the horizontal arm 22 is likewise proviced with a counterweight 24, which counterweights tend to rotate the dogs in a counter-clockwise direction to inoperative positions. Two stop rods 27 and 27 (see Figs. 1 and 2) carried by the yoke 26 limit the are through which the dogs can be rotated. The horizontal arm 21 is also provided with an upstanding projection 21' which co-operates with a resilient strip 18 attached to the interlocking arm 14?, while the horizontal arm 22" is provided with a similar upstanding projection 22 which co-operates with a resilient strip 18 attached to the interlocking arm When the armature 5 is released and drops, the strip 18 engages the projecment of the offset portion with the upper end of the vertical arm 21 The parts are so proportioned that when the offset portion 15 engages the vertical arm 21* in this manner, the armature 5 is held at approximately mid stroke, and both the front and back contacts controlled by the armature 5 are then open. Furthermore, when the offset portion 15" engages the vertical arm 21 in this manner, a tip 17, formed on the end of a retaining spring 16 attached to the interlocking arm 14, extends downwardly past the lefthand edge of the upper end of the vertical arm 21 as viewed in Fig. 2, thus holding the dog 21 underneath'the ofiset portion 15, and thereby insuring that armature 5 can not move to the position in which its back contacts are closed. When electromagnets A and B again both become energized, so that the armatures are both moved to their upper positions, the counterweight 23 returns the dog 21 to its inoperative position against the stop rod 27 in which position the vertical arm 21 is out of the path of movement of the ofiset portion 15 The locking dog 2270perates in a manner similar to the locking dog 21, as will readily be apparent from an inspection of the drawings, but serves, when actuated by the resilient strip 18 attached to the'interlockingarm 14 to limit the downward movement of the armature 5 I If both armatures are released at the same time, so that both armatures move toward their lower positions simultaneously, tip 17 a on retaining spring 16 engages the upper end of the vertical arm 21 of the dog 21, and at substantially the same time, the corresponding tip 1.7. on retaining spring 18 engage the upper end of the vertical arm .22 of arm 22. F lexure of retaining springs .16 and 16 permits further downward movement of the armatures 5 and 5 and as a result,

- the strip 18 engages the projection21 on the horizontal arm 21 of dog 21 at the same time that the strip 18 engages the projection 22 on the horizontal arm 22 of dog 22, and

both dogs are therefore rotated in a clock wise direction in unison. The parts are so proportioned, however, that, under these conditions, neither of the dogs 21 or 22 is rotated to a position in which the upper end of its vertical arm 21 or 22*, respectively, is in the path of movement of the associated offset portion 15* or 15 and the offset portion 15 p of the interlocking arm 1 1 therefore moves past the upper end of the vertical arm 21 of the dog 21, and the offset portion 15 of the interlocking arm 1r moves past the upper end of the vertical arm 22 of the dog 22. Shortly after the ofiset portion 15 passes the upper end of the vertical arm 21 however, theright-hand side of the vertical arm 21 as viewed in Figs. 2 or 8, moves against the end of the offset portion 15 and, at the same time, the right-hand side of the vertical arm 22 moves against the end of the offset portion 15 It will be apparent, therefore, that further downward'movement of armature 5 is opposed by the retaining spring 16 and by the resilient strip 18 while further downward movement of armature 5 is op-- posed by the retaining spring 16 and by the resilient strip 18*. v

It should be pointed out that the dogs 21 and 22 are very light in weight, and are loosely pivoted on the shaft 25 so that the force required to drive these dogs is small. The strips 18 and 18 need only bestiil enough to drive the dogs 21 and 22 without causing deflection of the strips, and it will be apparent, therefore, that these strips may be constructed to bend under comparatively small pressure. If desired, back stops 19% 19 of rigid material may be'p rovided to determine accurately the position at which the strips 18 or 18 will engage the dogs during the downward stroke of the armatures. Furthermore, top stops 20 20 may also be provided with clearance above the strips, so that if some unusual resistance to the movement of the dogs should develop which would cause abnormal deflectionof a strip 18 or 18 the associated top stop 2O or 20 would engage the strip, and would limit the amount of deflection ofthe strip, so that the corresponding locking dog would still be driven into the path of movement of associated offset portion 15 or 15 and past the tip 17 or 17* of the retaining spring 16 or 16".

The sole purpose of retaining springs 16 and 16 is to hold the ends'of dogs 21 and 22 under the fingers 15 and 15 when the parts are locked. These springs 16 and 16 areso proportioned, that these springs are very flexible, and the strips 18 and18 are also very flexible, as explained in detail hereinbefore, so that the resistance offered to the downward movement of the armature 5 by the retaining spring 16 and strip 18 and to the armature 5 by the retaining spring 16 and strip 18', is slight. As a result, both armatures 5 and 5 move to their lowermost positions and close their back contacts with substantially the same contact pressure as they would if the interlocking arms were not attached to the armatures.

One advantage of a relay embodying our invention is that due to the use of resilient strips for driving the locking dogs, a higher backcontact pressure is obtained when both armatures are released simultaneously than would otherwise be possible under these conditions. Furthermore, due to the use of the resilient strips for driving the dogs, the limits of adjustment of the various parts of the interlocking mechanism necessary for satisfactory operation are considerably greater than would otherwise be possible, thus greatly simplifying the manufacture of the relay.

Although we have herein shown and described only one form of relay embodying our invention, it isunderstood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of our invention.

Having thus described our invention, what we claim is: I

1. An interlocking relay comprising two electromagnets, two armatures one controlled by each electromagnet, two resilient members one attached toeach armature, two dogs one actuated by each member, and rigid means separately controlled by said armatures and separately co-acting with said dogs for restricting the movement of one armature when one of said dogs is actuated by the member attached to the other armature.

2.-An interlocking relay comprising two electromagnets, two armatures one controlled by each electromagnet, two yieldable members one attached to each armature, two dogs one actuated by each member, and means separately controlled by said armatures and separately co-acting with said dogs for restricting the movement of one armature when one of said dogs is actuated by the member attached to the other armature.

3. An interlocking relay comprising two electromagnets, two armatures one controlled by each of said electromagnets, two dogs each capable of assuming a plurality of positions, resilient means attached to each armature for at times moving an associated one of said dogs from a first position to a second position, and rigid means attached to each of said armatures and co-operating with the dog which is controlled by the other said armature for restricting the movement of the armature to which said rigid means is attached when such co-operating dog occupies its second position.

4. An interlocking relay comprising two electromagnets, two armatures one controlled by each of said electromagnets, two dogs each capable of assuming a plurality of positions, resilient means attached to one of said armatures for at times moving one of said dogs from a first position to a second position, and rigid means attached to the other said armature and co-acting with said one dog for restricting the movement of said other armature when said one dog occupies its second position.

5. An interlocking relay comprising two electromagnets, two armatures one controlled by each electromagnet, two movable locking dogs, resilient means attached to one said armature for at times moving one said dog from a first position to a second position, resilient means attachedto the other armature for at times moving the other said dog from a first position to a second position, and rigid means separately controlled by said armatures and separatelyco-acting with said dogs for restricting the movement of either armature if the dog controlled by the remainingarmature occupies its second position.

6. An interlocking relay comprising two electromagnets, two armatures one movable toward and away from each electromagnet according as such electromagnet is energized or ole-energized, two movable dogs, resilient means attached to one said armature for at imes moving one said dog from a first position to a second position when said one armature moves away from its associated electromagnet, resilient means attached to the other said armature for at times moving the other said dog from a first position to a second position when said other armature moves away from its associated electromagnet, and rigid means separately controlled by said armature and separately co-operating with said dogs for restricting the movement of either armature away from its associated electromagnet when and only when the remaining armature has previously moved away from its associated electromagnet.

7. An interlocking relay comprising two electromagnets, two armatures one movable toward and away from each electromagnet according as such electromagnet is energized or de-energized, a dog biased to a first position, resilient means attached to one said armature for at times moving said dog from said first position to a second position when said one armature moves away from its associated electromagnet, and means co-operating with said dog when said dog occupies its second position for limiting the movement of the other said armature away from its associated electromagnet, said resilient means being constructed to yield if the resistance to movement of said dog exceeds its normal value.

8. An interlocking relay comprising two electromagnets, a first armature controlled by one electromagnet and a second armature controlled by the other electromagnet, a first and a second movable locking dog each having a first and a second position, a first resilient strip attached to said first armature for at times moving said first dog from its first position to its second position, a second resilient strip attached to said second armature for at times moving said second dog from its first position to its second position, rigid means attached to said first armature and coacting with said second dog for limiting the movement of said first armature away from its associated electromagnet when said second dog occupies its second position, and rigid means attached to said second armature and co-acting with said first dog for limiting the movement of said second armature away from its associated electromagnet when said first dog occupies its second position.

9. An interlocking relay comprising two electromagnets, two armatures one controlled by each electromagnet, a pivoted locking dog having a horizontal arm provided at one end with a counterweight and at the other end with an upstanding projection and also having a vertical arm, a resilient strip attached to one said armature and co-acting with said dog at said projection for actuating said dog, and an interlocking arm attached to the other armature and provided with an offset portion for at times engaging said vertical arm when said dog is actuated to limit the movement of the other said armature. Y

10. An interlocking relay comprising two electromagnets, two armatures one controlled by each electromagnet,a pivoted locking dog having a horizontal arm provided at one end with a counterweight and at the other end with an upstanding projection and also having a vertical arm, a. resilient strip attached to one said armature and co-acting with said arm at said projection for at times moving said dog from a first position to a second position, an interlocking arm attached to the other said armature and provided with an ofiset portion for engaging said vertical arm when said dog occupies its second position to limit the movement of said other armature away from its associated electromagnet, and a retaining'spring attached to said second arm and provided on its free end with a tip adapted to hold said dog in its second position when said ofiset portion is in engagement with said vertical arm.

11. An interlocking relay comprising two electromagnets, two armatures one controlled by each electromagnet, a pivoted locking dog having a horizontal arm provided at one end with a counterweight and at the other end with an upstanding projection and also havinga vertical arm, a resilient strip attached 7 to one said armature and co-acting with said the movement of the other said armatureaway from its associated electromagnet.

12. An interlocking relay comprising two electromagnets, a first armature movable t0- ward and away from one said electromagnet, a second armature movable toward and away from the other said electromagnet, a first interlocking arm attached to said first armature and provided with an ofiset portion, a second interlocking arm attached to said second armature and pro 'ided with an offset portion, a first resilient strip attached to said first arm, a front'and back stop for said first strip attached to said first arm, a second resilient s rip attached to said second arm, a front and back stop for said second strip attached to said second arm, a first pivoted dog having a first horizontal arm provided at one end with a first counterweightand at the other end with a first upstanding projection and also having a first vertical locking arms in such manner that if said first armature moves away from its electromagnet said first resilient strip will engage said first dog at said first projection and rotate said first dog to an' operative position in which said first vertical arm will engage the offset portion or said second interlocking arm and limit the movement of said second armature if said second'armature subsequently moves away from its associated electromagnet; and a second pivoted dog having a second horizontal arm provided at one end with a second counterweight and at the other end with a second upstanding projection and also having a second vertical arm and meeting with said interlocking arms in such manner that if said second armature moves away from its associated electromagnet said second resilient strip will engage said second horizontal arm at said second projection and rotate said second dog to an operative position in which said second vertical arm will engage the offset portion of said first interlocking arm if said second armature subsequently moves away from its associated electromagnet.

13. An interlocking relay comprising two electro-magnet-s, a first armature controlled by one said electromagnet and a second armature controlled by the other said electromagnet, first and second movable looking dogs each having a first and a second position, a first resilient strip attached to said first armature for at times moving said first dog from its first position to its second position, a second resilient strip attached to said second armature for at times moving said second dog from its first position to its sec-- ond position, rigid means attached to said first armature and co-act'ng with said second dog for limiting the movement of said first armature away from its associated electromagnet when said second dog occupies its second position, rigid means attached to said arm and co-acting with said intersecond armature and co-acting with said first dog for limiting the movement of said second armature away from its associated electro magnet when said first dog occupies its second position, and front and back contacts separately controlled by said armatures and arranged in such manner that when the movement of one of said arma-tures away from its electromagnet is limited by one of said dogs the contacts controlled by such one armature are open.

14. An interlocking relay comprising a first and a second electromagnet, a first armature movable toward and away from said first electromagnet according as said first electromagnet is energized or de-energized, a second armature movable toward and away from said second electromagnet according as said second electromagnet is energized or deenergized, a first pivoted dogmovable between a first and a second position and having a horizontal arm provided at one end with a counterweight and at the other end with an upstanding projection and also having a vertical arm, a second pivoted dog mov able between a first and a second position and having a horizontal arm provided at one end with a counterweight and at the other end with an upstanding projection and also hav ing a vertical arm, a first interlocking arm attached to said first armature and provided with an offset portion adapted to engage the vertical arm of said first dog to limit the movementof said first armature away from said first electromagnet to approximately mid stroke if said first dog occupies its second position when said first electromagnet becomes de-energized, a second interlocking arm attached to said second armature and provided with an offset portion adapted to engage the vertical arm of said second dog to limit the movement of said second armature away from said second electromagnet to approximately mid stroke if said second dog occupies its second position when said second electromagnet becomes de-energized, a first resilient strip attached to said first interlocking arm and co-acting with the projection of said second dog for at times moving said second dog from its first to its second position when said first armature moves away from said first electro-magnet, a second resilient strip attached to said second interlocking arm and co-acting with the projection of said first dog for at other times moving said first dog from its first position to its second posi tion when said second armature moves away from said second electromagnet, said strips and said dogs being so proportioned that if both said armatures move away from their associated electromagnets simultaneously both said ofi'set portions will move past the upper ends of said vertical arms and permit both said armatures to move their full stroke tures.

WILLIAM K. LOCKHART. THOMAS J. OMEARA. 

